Arrangement of a power semiconductor circuit

BACKGROUND OF THE INVENTION

0001(1) Field of the Invention

0002The present invention relates to a power electronic assembly with a heat sink, a power semiconductor module and a circuit arrangement for controlling the power semiconductor module.

0003Power semiconductor modules and associated circuit arrangements for controlling the power semiconductor modules are currently widely used. They frequently form parts of power supplies, converters, in particular inverters or rectifiers, or other electrical arrangements.

0004(2) Description of Related Art

0005It is presently customary to construct so-called stacks (for example, Prime Stacks from in Infinion AG) for each application or for a group of applications. These stacks have a heat sink on which a plurality of power semiconductor modules and the circuit arrangements associated with these powers semiconductor modules for controlling the modules are arranged.

0006When planning all applications of power electronics, the developer must pay particular attention to the cooling of the power electronic components. Depending on the thermal load, a coolant in liquid or gaseous form may have to be supplied to adequately dissipate heat. The power electronics in conventional applications is cooled individually. This increases the individuality of the assemblies.

0007The high degree of individuality and particularly the associated development complexity have associated costs which make the finished product more expensive.

0008This is a starting point for the present invention.

0009It is the object of the invention to propose a power electronic assembly which offers many possible different applications through different possibilities for adequate cooling.

BRIEF SUMMARY OF THE INVENTION

0010This object is solved with the invention by employing a heat sink with at least two parallel channels through which a coolant flows.

0011The assembly according to the invention can be used in many different ways. Initially, at low thermal load, the assembly can be used entirely without a coolant flowing through the channels. The heat capacity and the heat transport through radiation and convection are sufficient for dissipating the generated heat. At greater thermal loads, heat can be dissipated with a coolant flowing at least through a portion of the channels. The medium may be a gas, for example air, or a fluid, for example water or oil. In particular at high thermal loads, a fluid flows preferably through at least a portion of the channels.

0012The cooling power can be adapted to different applications by using a heat sink.

0013The parallel design of the channels facilitates the manufacture of the heat sinks, which are typically produced from an extruded profile or machined, for example drilling or milling, from an aluminum block.

0014The channels may also be connected with one another by at least one first connecting channel. The channels can be connected inside the heat sink by way of these connecting channels. The connecting channels can be produced by drilling or other suitable machining. The channels can be connected in parallel or in series for fluid conduction. The series connection can be implemented inside the heat sink or by lines arranged outside the heat sink and connecting the channels.

0015In the heat sink of a power electronic assembly according to the invention, a first plurality of first adjacent channels of the channels may form supply channels having end regions which are connected with one another via the first connecting channel. A second plurality of second adjacent channels of the channels may form return channels having start regions which are connected with one another via the first connecting channel and which are connected with the end regions of the supply channels. With this connection, the supply channels and the return channels may be connected in series by way of the connecting channel for fluid conduction. The first plurality and the second plurality may have identical size.

0016Start regions of the supply channels may be connected via a second connecting channel and end regions of the return channels may be connected via third connecting channels.

0017Preferably, fittings for connecting the channels to supply lines or return lines may be provided in the start region of the supply channels and in the end region of the return channels.

0018The channels and/or the connecting channels in the heat sink of a power electronic assembly according to the invention may be implemented as sections of through-holes and/or blind holes in a block which forms the heat sink. The sections of the through-holes and/or blind holes may be delimited by stoppers, screws and the like. The through-holes and/or the blind holes may be subdivided by the stoppers, screws or the like into sections forming one or several channels. The block with the through-holes and/or the blind holes can thereby be adapted to the individual requirements of a power electronic assembly to be produced with the block forming the heat sink, without requiring an entirely new design of a heat sink.

0019The stoppers, screws or the like can be glued or releasably inserted into the block.

0020The channels in the heat sink can be configured by placing or removing stoppers, screws or the like. In this way, several channel systems can be configured for adapting the heat sink to different thermal loads.

0021Like stoppers, screws or the like, fittings can be releasably inserted into the block to provide inlets or outlets for the coolant at different locations.

0022Preferably, the stoppers and the fittings can be selectively inserted into the end of one of the holes (through-holes or blind holds).

0023The power semiconductor module is preferably mounted on the heat sink to ensure good thermal transport from the power semiconductor module to the heat sink.

0024The circuit arrangement for controlling the power semiconductor module may be arranged on a circuit carrier which may be attached on the heat sink with spacers in spaced relationship from the surface of the heat sink. The circuit board may have an opening into which the power semiconductor module penetrates or through which the power semiconductor module extends.

0025The heat sink of a power electronic assembly according to the invention may have on a side facing away from the power semiconductor module at least one groove, at least one bore, in particular with an internal thread, at least one screw channel and the like, in which fasting means for mounting the power electronic assembly to a carrier are provided.

0026Advantageously, the power electronic assembly according to the invention has exactly one power semiconductor module and exactly one circuit arrangement for controlling just this module. Typically, such power electronic assembly according to the invention is unable to realize a complete power-electronics arrangement, for example a converter. Several, at least two power electronic assemblies according to the invention are therefore used for an arrangement according to the invention.

0027A power electronic assembly according to the invention may also have two different power semiconductor modules on one heat sink, wherein the power semiconductor modules are preferably used in different converters. This is of particular interest for arrangement where two converters, namely an input-side and an output-side converter are implemented, for example in a frequency converter which includes a rectifier, a DC link circuit and an inverter. Because the power electronic assembly then advantageously includes only one power semiconductor module of the input side converter and one power semiconductor module of the output side converter, the arrangement according to the invention must therefore also have several power semiconductor modules. The heat sink for attachment of two power semiconductor modules may then need to be constructed in a particular manner, for example with planar surfaces arranged on both sides of the heat sink. These may be produced by further machining a heat sink or may already be initially provided.

0028The power electronic assembly can be arranged with respect to one another so that the channels are parallel to one another.

0029The arrangement may have inlets and outlets for a coolant which are connected to the supply channels and return channels, respectively, with fittings arranged in the start regions of the supply channels and in the end regions of the return channels.

0030The power electronic assemblies may be connected in parallel for fluid conduction.

0031The power electronic assemblies of an arrangement according to the invention may be identical.

0032The power electronic assemblies may be mounted on at least one carrier, for example a mounting rail.

0033An exemplary embodiment of a power electronic assembly according to the invention and an arrangement which includes two of these assemblies will be described in more detail with reference to the drawings. It is shown in

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

0034<figref idref="DRAWINGS">FIG. 1</figref> a perspective view of the arrangement according to the invention,

0035<figref idref="DRAWINGS">FIGS. 2</figref><i>a </i>to <b>2</b><i>c </i>the power electronic assembly in different views, and

0036<figref idref="DRAWINGS">FIGS. 3</figref><i>a </i>to <b>3</b><i>e </i>a heat sink of the power electronic assembly according to <figref idref="DRAWINGS">FIGS. 2</figref><i>a </i>to <b>2</b><i>c </i>in different views.

DETAILED DESCRIPTION OF THE INVENTION

0037The arrangement according to the invention may be part of, for example, a frequency converter. A typical frequency converter includes an input rectifier, a DC link circuit and an output inverter. The exemplary arrangement according to the invention illustrated in <figref idref="DRAWINGS">FIG. 1</figref> forms the output inverter A of a frequency converter. However, arrangements according to the invention may also form other circuits.

0038The output inverter A generates a single-phase AC current from the DC current of the DC link circuit. For generating the AC current, the output inverter includes bipolar transistors with insulated gate electrodes (IGBTs), which are connected in form of an H-circuit. This conventional circuit for generating single-phase AC current requires four IGBTs. Two IGBTs are each housed in a power semiconductor module <b>1</b>. Such power semiconductor modules <b>1</b> are offered by several manufacturers.

0039The power semiconductor modules <b>1</b> are combined with a circuit arrangement <b>3</b> for controlling the power semiconductor modules <b>1</b>, which includes a circuit carrier <b>31</b> and components <b>32</b> arranged thereon, and with a heat sink <b>2</b> to form a power electronic assembly <b>1</b>, <b>2</b>, <b>3</b> (see <figref idref="DRAWINGS">FIGS. 2</figref><i>a </i>to <b>2</b><i>b</i>). The arrangement A according to the invention has two such power electronic assemblies <b>1</b>, <b>2</b>, <b>3</b> which are mounted on two mounting rails <b>4</b>.

0040Power electronic assemblies according to the invention may also include power semiconductor modules other than IGBT power semiconductor modules. An arrangement according to the invention may also include more than two power electronic assemblies.

0041Different circuits may be realized with power electronic assemblies <b>1</b>, <b>2</b>, <b>3</b> according to the invention. For example, the IGBTs of the IGBT power semiconductor modules in the aforementioned H-circuit may also be connected in a different bridge circuit or in any type of midpoint connection. The IGBT power electronic modules themselves need not be altered at all or need only be altered slightly. Simple changes may be performed by suitable programming. Optionally, a component in the control circuit arrangement <b>3</b> may have to be changed. In the most complex case, the entire control circuit arrangement <b>3</b> may have to be exchanged. The heat sink <b>2</b> may only have to be changed in response to a change in the thermal load, for example because additional power semiconductor modules are to be mounted. However, the heat sink can be easily changed, as will be described below.

0042In particular, these simple changes of an arrangement according to the invention, particularly also a simple scalability of an arrangement according to the invention, becomes possible due to the association of the heat sink <b>2</b> with a power semiconductor module.

0043The power semiconductor module <b>1</b> is preferably mounted directly on the heat sink <b>2</b>, allowing an efficient heat transfer from the thermally heavily loaded power semiconductor module <b>1</b> to the heat sink.

0044The circuit arrangement <b>3</b> is preferably mounted on the heat sink with spacers <b>33</b>, wherein the circuit carrier <b>31</b> of the circuit arrangement <b>3</b> may have an opening through which parts of the power semiconductor module <b>1</b> protrude.

0045The heat sink <b>2</b> is designed for easy adaptation to different thermal loads.

0046The cooling body is produced from an extruded aluminum profile. The extruded profile is hereby produced with four parallel first holes extending in the longitudinal direction, namely through-holes <b>21</b>. In an end region of these through-holes <b>21</b> and transverse to the first through-holes <b>21</b>, the extruded profile includes a second hole, namely a through-hole <b>22</b>, which intersects with the first through-holes <b>21</b>. A third hole, namely a blind hole <b>23</b>, and a fourth hole, namely a blind hole <b>24</b>, which each intersect two of the first through-holes <b>21</b>, are introduced from two different sides in an end region located opposite the second through-hole <b>22</b>.

0047Threads <b>25</b> are cut at the ends of the through-holes <b>21</b>, <b>22</b> and at the ends of the blind holes <b>23</b>, <b>24</b>, into which stoppers <b>26</b> which close the holes <b>21</b>, <b>22</b>, <b>23</b>, <b>24</b> are screwed and/or glued.

0048Additional blind holes are introduced from a top side of the heat sink, which open into the third hole <b>23</b> and the fourth hole <b>24</b>. Fittings <b>29</b> are inserted in these additional blind holes. These fittings <b>29</b> form an inlet and an outlet for the channel system formed in the cuboid by the holes <b>21</b>, <b>22</b>, <b>23</b>, <b>24</b> from channels (formed by the sections of the first holes <b>21</b>), a first connecting channel (formed by a section of the second hole <b>22</b>), a third connecting channel (formed by a section of the third hole <b>23</b>) and a fourth connecting channel (is formed by a section of the fourth hole <b>24</b>). The sections of the holes forming channels or connecting channels are delimited by the material of the cuboid and the stoppers <b>26</b>.

0049Two of the channels form supply channels which start at one of the two fittings <b>29</b> which forms an inlet and terminate at the first connecting channel formed by a section of the second hole <b>22</b>. The two other channels form return channels which start at the first connecting channel and terminate at one of the other two fittings <b>22</b>. These fittings then form an outlet. A coolant can thus flow from the inlet to the outlet through the heat sink.

0050In an alternative embodiment, the stoppers <b>26</b> which close the first holes <b>21</b> and are screwed into the end faces of the cuboid, may be removed and replaced by fittings. If the existing fittings <b>29</b> are replaced by stoppers, the coolant can then flow from one end face to the other end face of the heat sink and dissipate a larger amount of heat from the heat sink. The heat sink can thereby be adapted to the expected thermal load by using simple measures.